1. Field of the Invention
The present invention pertains to an appliance having an outer shell within which is positioned a liner having walls which are spaced from the outer shell so as to define an insulation zone therebetween and, more particularly, to a support arrangement used to mount a shelf extending across the liner walls in such an appliance, as well as a method of supporting the shelf in the appliance.
2. Discussion of the Prior Art
In various types of appliances, it is common to provide some structure which will enable one or more shelves to be mounted within a given appliance compartment. For example, in a common household refrigerator, numerous shelves will be provided in order to enable various items to be supported at different vertical storage positions. In the prior art, these shelves are typically supported through specific mounting structure within the refrigerator. Such known mounting structure includes: integrally forming shelf supporting rails with a molded liner that defines the interior walls of a given refrigerator compartment; securing mounting brackets to opposing side walls of the liner through the use of threaded fasteners; and positioning mounting supports or grommets within apertures formed in the liner. Since it is highly desirable to permit the shelves to be vertically adjusted to selectively configure the overall shelving arrangement so as to accommodate varying sized items to be supported, multiple levels of these known mounting structures are generally provided in refrigerators.
When forming the liner of a refrigerator or other appliance, it is desirable to minimize the required thickness of the liner to reduce manufacturing costs. When the liner is integrally formed with the shelf supporting rails, the liner must be inherently thickened at the rails to some extent in order to assure that the rails will not fail under load conditions. Therefore, forming the shelf supporting structure in this manner generally adds to the manufacturing cost of the liner. In addition, if such a support rail were to fail or become damaged during use, serviceability is greatly limited.
Forming the mounting structure by attaching threaded fastener secured brackets to opposing side-walls of the liner provides for enhanced servicing in the case of part failure since a new bracket can be readily installed in place of the damaged bracket. However, since any given shelf will generally require four or more mounting brackets and numerous shelves will be provided in each appliance, the original appliance assembly can be quite cumbersome and time consuming. In addition, this type of mounting structure has several parts which itself can add to the cost associated with the manufacturing of the appliance.
Attaching mounting supports or grommets in the liner walls in order to support shelves therefrom advantageously reduces the number of supporting components and can simplify the assembly process. With most known arrangements, the mounting supports are, for the most part, retained in a desired position due to an in situ foaming process. More specifically, body portions of the mounting supports are generally inserted, from a refrigerated compartment side, within apertures provided in the opposing side walls of the liner after the liner has been placed in an outer cabinet shell of the refrigerator or other appliance. Thereafter, the space between the liner and the cabinet shell is injected with foamed insulation which will inherently flow about the body portions of the mounting supports. Once solidified, the insulation will securely retain the mounting structure in the desired position.
Of course, such an arrangement requires that the mounting supports be held in the desired position during the insulation injection process. Since the mounting support is inserted in the aperture from the refrigerated side of the liner, the mounting support can be undesirably pushed back through the aperture during the foaming operation as the insulation bears against a wall of the support. To this end, it has been proposed to provide the mounting support with an annular flange at one end and locating structure on the body portion of the support at a position spaced from the annular flange a distance equal to the thickness of the liner. With this arrangement, the support can be inserted into a respective aperture until the liner is arranged between the annular flange and the locating structure to hold the support in the desired position for the foaming operation. Unfortunately, this mounting support arrangement requires a rather fine degree of tolerance between the thickness of the liner and the distance between the annular flange and the locating structure in order to assure that the mounting support will be retained in the desired position and the foamed insulation will not leak into the cabinet compartment.
In view of the above, there exists a need in the art for a shelf mounting support arrangement that can be readily installed within apertures of an appliance liner with minimal effort, time and associated cost, and which can be easily retained in a desired position before and during the insulating process, while avoiding the need for high manufacturing tolerances but assuring that the foamed insulation will not leak into the interior of the liner or undesirably displace the mounting support.
A support arrangement is provided for mounting a shelf in a compartment of an appliance having an outer shell within which is positioned a compartment defining liner having walls spaced from the outer shell so as to define an insulation zone therebetween. The mounting support includes an annular flange portion and a body portion that projects from the annular flange. The body portion, upon which a shelf is to be supported, is adapted to be placed into an aperture formed in a side wall of the liner from the insulation zone side of the liner, while the annular flange portion is positioned against an outer wall surface of the liner.
In order to retain the mounting support in a desired position prior to injecting foamed insulation into the insulation zone in accordance with a first embodiment of the invention, an adhesive element is used to secure the annular flange portion to the liner. With this arrangement, the mounting support can be easily attached to an outer side wall surface of the liner in a desired position and retained in this position by the adhesive element. Thereafter, foamed insulation can be injected into the insulation zone in order to further anchor the mounting support.
In accordance with a further embodiment of the invention, instead of utilizing the adhesive element, the body portion of the mounting support is provided with a plurality of annularly spaced, deflectable grip fingers. The fingers function to engage an inner surface of the liner upon insertion. In order to account for variations in differing thermoformed liner thicknesses, the annular flange includes an outermost radial portion which is thin and flexible so as to deflect due to abutment with the liner upon insertion of the mounting support in order to provide an enhanced seal between the flange and the liner. Furthermore, to enhance the defecting of the flange in accordance with the most preferred form of this embodiment of the invention, the flange has a diameter which is at least three times the diameter of the body portion. In addition, the outermost radial tip of the flange, prior to insertion of the mounting support, is located in a plane that extends through at least a portion of the grip fingers.
To aid in the interengagement between the liner and the mounting support in accordance with each of the disclosed embodiments, while also structurally reinforcing the overall support arrangement, the body portion is advantageously provided with an internal cavity into which the insulation flows. In accordance with certain embodiments of the invention which is particularly adapted to use in mounting certain types of shelving units in a refrigerator, a terminal end of the body portion is formed with an annular groove adapted to receive a portion of a shelf to maintain a desired positioning of the shelf regardless of any shrinkage of the liner upon cooling of the enclosure. A method of mounting a shelf utilizing such a support arrangement is also provided in accordance with the invention.
Additional features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments of the invention when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.